Boveda Butler for Herbal Medicine | Smart Hygrometer That Measures RH and Temperature with Auto Alerts to Your Phone | Easy-to-Use Calibration Kit | App Available on iOS and Android | 1-Count

It worked well for quite a while, but now it seems to disconnect from my phone and refuses to reconnect until I remove the battery and put it back in. Then it lasts maybe a day before I need to do it again.